Dancing Queen

The challenge gives us the description that there is some ChaCha20 implementation, and searching Google for the name of the challenge shows some hints about this implementation being done “incorrectly”. Hence we should take a look at the way that ChaCha20 is supposed to be implemented. One good resource is RFC 8439, clicking on the link should take you to the page that contains the high-level pseudocode of how ChaCha20 works....